Valvular Heart Disease: Common Types and Management for PLAB 1
Understanding valvular heart disease is crucial for the PLAB 1 exam. This module covers the most common types of valvular heart disease, their pathophysiology, clinical presentation, and general management principles. This knowledge is essential for diagnosing and managing patients effectively in a UK medical setting.
Introduction to Heart Valves
The heart has four main valves: the mitral, tricuspid, aortic, and pulmonary valves. These valves ensure unidirectional blood flow through the heart chambers. Dysfunction of these valves can lead to significant haemodynamic consequences.
Common Types of Valvular Heart Disease
Valvular heart disease can be broadly categorized into stenosis (narrowing of the valve opening) and regurgitation (incompetent valve allowing backflow). The most commonly affected valves in adults are the aortic and mitral valves.
| Valve | Common Stenosis | Common Regurgitation | Typical Cause (Stenosis) | Typical Cause (Regurgitation) |
|---|---|---|---|---|
| Aortic | Aortic Stenosis (AS) | Aortic Regurgitation (AR) | Degenerative calcification, Bicuspid aortic valve | Aortic root dilation, Bicuspid aortic valve, Rheumatic heart disease |
| Mitral | Mitral Stenosis (MS) | Mitral Regurgitation (MR) | Rheumatic heart disease | Mitral valve prolapse, Rheumatic heart disease, Ischemic heart disease, Dilated cardiomyopathy |
| Tricuspid | Tricuspid Stenosis (TS) | Tricuspid Regurgitation (TR) | Rheumatic heart disease, Carcinoid syndrome | Pulmonary hypertension, Tricuspid valve prolapse, Rheumatic heart disease |
| Pulmonary | Pulmonary Stenosis (PS) | Pulmonary Regurgitation (PR) | Congenital (e.g., Tetralogy of Fallot) | Pulmonary hypertension, Infective endocarditis |
Aortic Stenosis (AS)
Mitral Regurgitation (MR)
Mitral Stenosis (MS)
Aortic Regurgitation (AR)
Diagnosis of Valvular Heart Disease
Diagnosis relies on a combination of clinical history, physical examination, and investigations. Key investigations include:
Echocardiography (transthoracic and transesophageal).
Other important investigations include ECG (to detect arrhythmias like atrial fibrillation or signs of ventricular hypertrophy), chest X-ray (to assess heart size and pulmonary congestion), and cardiac catheterization (for detailed haemodynamic assessment and coronary angiography if indicated).
Management Principles
Management strategies depend on the specific valve affected, the severity of the disease, the presence of symptoms, and the patient's overall health. General principles include:
The goal of management is to alleviate symptoms, prevent complications (like heart failure, thromboembolism, and endocarditis), and improve quality of life.
Management options can be broadly divided into medical and surgical/interventional.
Medical Management
Medical management is primarily for symptomatic relief and prevention of complications. This may include:
- Diuretics for fluid overload and pulmonary congestion.
- ACE inhibitors or ARBs for afterload reduction, especially in regurgitant lesions.
- Beta-blockers or rate-controlling agents for atrial fibrillation.
- Anticoagulation for patients with atrial fibrillation or mechanical prosthetic valves.
- Antibiotic prophylaxis for infective endocarditis, particularly in patients with prosthetic valves or certain congenital defects.
Surgical and Interventional Management
Surgical intervention is indicated for severe symptomatic valvular disease or asymptomatic severe disease with evidence of haemodynamic compromise or impending risk. Options include:
- Valve Repair: Preferred when possible, aiming to restore normal valve function.
- Valve Replacement: With either mechanical prostheses (requiring lifelong anticoagulation) or bioprosthetic valves (which have a limited lifespan).
- Transcatheter Aortic Valve Implantation (TAVI/TAVR): A less invasive option for aortic stenosis, particularly in patients at high surgical risk.
Mechanical valves require lifelong anticoagulation (e.g., warfarin), while bioprosthetic valves do not, but have a limited lifespan.
Key Takeaways for PLAB 1
Focus on the common valvular lesions (AS, MR, MS, AR), their typical causes, characteristic murmurs, key symptoms, and the primary investigations. Understand the general principles of medical and surgical management, including the indications for intervention and the differences between valve replacement types.
Learning Resources
Provides a patient-friendly overview of heart valve disease, its causes, symptoms, and treatments from the British Heart Foundation.
A comprehensive overview of aortic stenosis, including symptoms, causes, diagnosis, and treatment options from Mayo Clinic.
Detailed information on mitral regurgitation, covering its causes, symptoms, diagnostic methods, and treatment strategies from Mayo Clinic.
An in-depth guide to mitral stenosis, including its causes, symptoms, diagnosis, and management from Mayo Clinic.
Explores aortic regurgitation, detailing its symptoms, causes, diagnostic approaches, and treatment options from Mayo Clinic.
Official clinical guidelines from the National Institute for Health and Care Excellence (NICE) on the management of valvular heart disease in adults.
An overview of heart valve disease from the American Heart Association, covering types, causes, symptoms, and diagnostic methods.
A review article discussing the role and interpretation of echocardiography in the diagnosis and management of valvular heart disease.
Information from the NHS on heart valve surgery, including when it's needed, the different types of procedures, and recovery.
A detailed medical overview of valvular heart disease, including pathophysiology, clinical presentation, diagnosis, and management, suitable for healthcare professionals.